Ads for pot are growing so fast in part because they face fewer regulations and restrictions than marketing materials for cigarettes and alcohol. The only real regulation is one requiring the ads to warn customers that they need a doctor’s recommendation.

“Marijuana advertising is a small percentage of our total advertising — we wish that we had more,” said Mina Bajraktarevic, advertising sales manager at the Bay Guardian, whose back page has become a wall of green with medical marijuana advertising.

“We’ve been involved in this for years,” said Bruce Brugmann, publisher of the Bay Guardian. “We haven’t heard any complaints.”

Not all media companies are comfortable with pot ads, and some have equivocated about whether to accept them. Some advertisers were waiting to see the outcome of the vote Nov. 2 on Proposition 19, the state pot legalization bill, before agreeing to take money from the burgeoning industry.

Ten years ago most medical cannabis clubs were intentionally low-key and relied only on word of mouth. Being illegal, they were inconsistently tolerated by the authorities.

Now, with rapidly liberalized enforcement policies, the most successful medical cannabis businesses are the ones that get their brand name out to the public. Dozens of the businesses are racing to capture the pot-smoking community’s mindshare, and are pumping hundreds of thousands of dollars into local media this year to do so.

“We probably spend around $2,500 to $3,000 a month on advertising,” said Kevin Reed, president of the Green Cross, a medical cannabis dispensary on Market Street between Eighth and Ninth streets. “We’re in a world where you’re competing with all these fly-by-night businesses who don’t have to follow the rules — they’re not regulated.” Until recently, more than half a dozen dispensaries had failed to register their businesses with the San Francisco Department of Public Health.

One of the pioneers of pot advertising was KUSF Radio. Four years ago, the station, run by the University of San Francisco, had a Green Cross-underwritten public-service announcement that ran on 90.3 FM.

But sometimes it’s hard for pot clubs to buy ads; several have lined up ad agreements only to have them retroactively rejected.

In May, Facebook canceled the Green Cross’ existing advertisements on the site. MediCann, a group of clinics specializing in medical marijuana evaluations, also had its Facebook ads snuffed.

In August, the Green Cross paid in full for a slot on a huge electronic billboard on Interstate 280 at the Serramonte Shopping Center in Daly City — only to see it taken down a day later.

The circumstances surrounding that reversal were not quite clear. SF Weekly ran a blog post suggesting the ad was taken down because its content was objectionable. But a spokeswoman for the mall, Cherie Napier, said that the real reason was that the billboard was only permitted to run ads for products or services sold at the mall. The marijuana ad, she said in an e-mail, “would have been a violation and could have resulted in a $10,000 fine from the state.”

Aside from the weeklies, the medical pot business supports a whole genre of “cannabis friendly” magazines, such as West Coast Leaf and Kush.

“We don’t do general newspapers or anything like that,” said Adrian Moore, director of operations at 7 Stars Holistic Healing Center in Richmond.

Bigger news outlets don’t appear ready to take advertisements for marijuana, at least not yet.

To what extent can marijuana be advertised? Kris Hermes, executive director of the Oakland-based Americans for Safe Access, called advertising for the drug a First Amendment issue.

“Our rough position is that we’re in favor of patients finding out how to access medical marijuana,” Hermes said. “We encourage local governments to figure out ways of allowing advertisements that aren’t counterproductive to [get to] the members of the community.”